Many modern in-vivo medical devices such as catheters or endoscopes are equipped with imaging equipment that includes a light source and an image sensor. A light source delivers an illumination light onto an area of interest while the image sensor obtains an image from the reflected or scattered illumination light. The images obtained are used by a physician to diagnose internal body tissue or to perform surgical procedures in the body.
The most common type of light sources used on catheters and endoscopes are lasers or high powered white light sources. Light from these external light sources is delivered to the distal end of the scope by a fiber-optic illumination channel. Alternatively, some devices have solid state light sources such as light-emitting diodes (LEDs) that are located at or adjacent the distal tip of the device. Both approaches have limitations. First, the optical fibers used to form an illumination channel are relatively fragile and limit the bending ability of the device. On the other hand, LEDs are often encapsulated in a plastic or other transparent material that is relatively large in comparison to the size of the light-emitting element. Therefore, the amount of light that can be delivered at the distal end of the device is limited by the diameter of the device. Therefore, there is a need for a light-emitting device that can be incorporated into a medical device such as an endoscope that avoids these limitations.